The last point to be considered in connection with the 7th of March speech is the ground then taken by Mr. Webster with reference to the extension of slavery. To this question the speech was chiefly directed, and it is the portion which has aroused the most heated discussion. What Mr. Webster’s views had always been on the subject of slavery extension every one knew then and knows now. He had been the steady and uncompromising opponent of the Southern policy, and in season and out of season, sometimes vehemently sometimes gently, but always with firmness and clearness, he had declared against it. The only question is, whether he departed from these often-expressed opinions on the 7th of March. In the speech itself he declared that he had not abated one jot in his views in this respect, and he argued at great length to prove his consistency, which, if it were to be easily seen of men, certainly needed neither defence nor explanation. The crucial point was, whether, in organizing the new territories, the principle of the Wilmot Proviso should be adopted as part of the measure. This famous proviso Mr. Webster had declared in 1847 to represent exactly his own views. He had then denied that the idea was the invention of any one man, and scouted the notion that on this doctrine there could be any difference of opinion among Whigs. On March 7 he announced that he would not have the proviso attached to the territorial bills, and should oppose any effort in that direction. The reasons he gave for this apparent change were, that nature had forbidden slavery in the newly-conquered regions, and that the proviso, under such circumstances,